1. Field of the Invention
The present invention relates to an apparatus for reproducing a coded voice signal (hereinafter referring to PCM signal). More particularly, it relates to a reproducing apparatus equipped with a calibrator for calibrating sudden level variation of reproduced sound caused at a connected part when a tape in which PCM signal is magnetically recorded, is compiled.
2. Description of the Prior Art
Apparatuses for recording and reproducing a PCM signal and for converting a voice signal to PCM signal so as to record it on magnetic recording tape, have been practically used.
FIG. 1 shows the recording pattern of these magnetic tapes wherein the reference numeral (1) designates a magnetic tape; (2a), (2b) . . . (2z) respectively designate recording parts in which each one word PCM signal is recorded; (3) designates an edited part; (4) designates a reproducing head; (31) designates a connected part of the magnetic tape (1). The magnetic tape (1) is driven in the arrow line direction to the magnetic head (4) and the PCM signal row as shown in FIG. 2 is detected by the magnetic head (4). The PCM signal row is decoded as the signal row (2) shown in FIG. 3(a) and the parts a and z in the edited part (3) are eliminated thereby reproducing it as the voice signal shown by the broken line in FIG. 3(b).
However, when the reproduction is carried out by eliminating the edited part (3) in which codes are lost, it is usual to cause a large level difference between Y and b as shown in FIG. 3(b) to give abnormal sound, disadvantageously.
When the conventional magnetic tape in which the analogue signal is recorded, is edited, the level difference in front of and in back of the connected part of the magnetic tape is gradually calibrated by cutting the magnetic tape in slant and bonding them. However, the magnetic tape in which a PCM signal is recorded, can not be easily calibrated in such a simple manner. The level difference caused in the connected part should be calibrated by an electrical method. Thus, reproducing apparatus having such calibrating function has not been obtained.